Study On The Smoking Behavior Of Schizophrenia And Related Molecular Genetics

Objective:1. To investigate the characteristic of smoking behavior about schizophrenia and enplore if smoking and nicotine addiction would be used as a quantitative endophenotype ;2. analyze the relationship between CHRNA7 on 15chr and schizophrenia and their smoking behavioral characters.Methods:1.all the schizophrenia and first degree relative were collected strictly with SCID ,and assessed by using investigation tools for nicotine addiction ,tea and coffee. And PANSS adopted for the patients. 2.A number of statistical tests including chi-squared test, ANOVA, Mann-Whitney U test, correlation analysis, partial correlation analysis and Nonparametric Tests were adopted to analyze the relation between smoking behavior and schizophrenia. 3.one single necleotide polymorphism(SNP) on CHRNA7 were analyzed through transmission disequilibrium analysis by using PDTPHASE program.Results:1.in this research, there were not significant difference in the propotion of sex between schizophrenia patients and there first-degree relatives,and the living time limit in city and age of the patients were lower than their relatives, but education time limit were higher; 2.the difference in the prevalence of smoking and tea between the schizophrenia patients and relative group were not significant; the smoking rate of female patients were 5.1%, male patients were 57.8% ,and the rate of female relatives were 1%, male relatives were 70.5%, which were not obviously different between patient group and relative group in either sex; compared with the relative group, the coffee drinking rate was higher in patients(OR=1.985), the smoke abatement rate was lower, the number of passive smoking was higher , and the propotion of which were in severe nicotine addiction was 28.4% in the patient group, higher than relative group in which was 13.2%; after removing the effect of age factor, there were not significant differences in the prevalence of smoking, tea drinking and coffee drinking between first-episode schizophrenia patients and recurrent patients; but the recurrent patients have severer nicotine addiction while compared to the first-episode ones.3.there were differences in smoking motivation between the patient smokers and relative smokers, the former mainly smoked for feeling comfortable, but the latter mainly for curiosity; compared to the relative smokers, the age of the patient smokers were low, and the smoke abatement time was less; the first smoking age, first regular smoking age and the maximum smoking age of the smoking subjects were all correlated to age, except for the severity of nicotine addiction, and the rank correlation coefficient were 0.339, 0.349 and 0.551 separately; after removing the effect of age factor, the living time limit in city of patient smokers was more than relative smokers, the maximum smoking age was low, but there were not any significant differences in the first smoking age, first regular smoking age and education time limit between the two group; after removing the effect of age and living time limit in city, the nicotine addiction level was severer in patient smokers than relative smokers. 4.between the male patient smokers and the male patient non-smokers, there were not any differences in education time limit, but the age and living time limit in city of the former were higher than the latter; the age influenced the patients, age of onset and course of disease; after removing the effect of age, living time limit in city and passive smoking factors, there were not obvious differences between the patient smokers and non-smokers; regarding the passive smoking number as concomitant variable, the conviarance analysis displayed that, the active smoking influenced the paranoia score of PANSS significantly, and the passive smoking influenced the aggressive score; regarding the passive smoking as concomitant variable, the partial correlation analysis displayed that, there was significant negative correlation between the nicotine addiction level and paranoia score with rank correlation coefficient–0.395 , and regarding the nicotine addiction level as concomitant variale, there were positive correlation between the passive smoking number and aggressive behavior score with rank correlation coefficient 0.396. 5.the first smoking age and first regular smoking age of male smoking patient were lower than age of onset, but maximum smoking age was higher, which prompted that patients smoked before disease onset, after that they smoked the most. 6.here were not significant association between either schizophrenia or status of smoking and the SNP in CHRNA7.Conclusion:there were not significant differences in smoking rate and first smoking age between the schizophrenia patients and their first degree relatives, but in the patient group, the maximum smoking age and smoke abatement rate were lower, smoke abatement time was shorter, nicotine addiction level was higher and the proportion of severe nicotine addiction was higher. The smoking motivation was different with the relatives too, the patients mainly smoke for feeling comfortable. There were significant negative correlation between the nicotine addiction level and paranoia score, positive correlation between the passive smoking number and aggressive behavior score. The nicotine addiction level of the recurrent patients was higher than the first-episode patients, and there were not any differences in smoking rate between the two group, patients usually smoked before disease onset, after that they smoked the most.